US Patent 7432565 III-V compound semiconductor heterostructure MOSFET device

A III-V based, implant free MOS heterostructure field-effect transistor device comprises a gate insulator layer overlying a compound semiconductor substrate; ohmic contacts coupled to the compound semiconductor substrate proximate opposite sides of an active device region defined within the compound semiconductor substrate; and a gate metal contact electrode formed on the gate insulator layer in a region between the ohmic contacts. The ohmic contacts have portions thereof that overlap with portions of the gate insulator layer within the active device region. The overlapping portions ensure avoidance of an undesirable gap formation between an edge of the ohmic contact and a corresponding edge of the gate insulator layer.